Signal-horn.



, Patented. Sept. 3, 1918..

2 SHEETS-SHEET 1- 1 I INIENTQR. M -M D. .B. HILL.

SIGNAL norm. APPLICATION FILED DEC. 16, I915.

Patented em. 3,191&

2 SHEETS-SHEET 2- A iio.

DWIGHT 1B. HILL, F BRIDG EPORT, CUIN'NJECTICUT.

SIGNAI-HORN.

newest.

- To all whom it may GO'IWGM.

Be it known that T, DWIGHT B. HILL, a citizen of theUnited States, residing in Bridgeport, county of Fairfield, and State of Connecticut, have invented certain new and useful Improvements in Signal-Horns,

of which the following is a full, clear, and

exact description. 1

I This invention relates to signal horns, and moreparticularly to a type of signal horn especially adapted for automobiles, in

which a'sound producing diaphragm is vi- 7 The inven-a brated by an electromagnet. tion also refers especially to a signal horn in which the electromagnet isenergized by a source of alternating current, such as amagneto, so as to causevibration of an ap- 'propriate armature, which in turn actuates the diaphragm.

\ One of the primary objects of the invention is'to provide a simple, reliableand inexpensive signalhornin which the current of the magneto Or-other generator is so utilized as to 'produce'a very sharp loud tone which rises above or penetrates the ordinary traffic noises so asto'attract immediate attention 'in crowded thoroughfares. The diaphragm and electromagnet are so arranged that in addition to the sustained tone promer blows, producing 'a peculiar raucous I noise. "Thus the total sound produced by the sustained tone and the hammer blows is sufficient to form a very efficient signal.

Another object of the invention is to provide'a signal horn in which the blow on the diaphragm is produced by moving the central portion of the latter in a direction countions 'of parts to be hereinafter described and claimed.

In the accompanying drawings, Figure -1 is a sideelevation of a signal horn embodying my improvements,

Fig. 2 is an enlarged elevation of the rear end portion of the horn, with certain parts shown in-section,

Fig. 3 is a vertical longitudinal section through the rear portion of the horn, shows Specification of Letters Patent. Pmtentpdl Sept. 3, llglllfic Application filed December 16, 1915. Serial No. 673%. I

ing the armature disk or button in a somewhat different adjustment from that illustrated in Fig. 2,

Fig. 4 is a front elevation of the rear sec tion carrying the electromagnet showing it detached from the other parts. 7

Fig. 4 is a fragmentary-detail of the dia- P Fig. 5 is a section on the irregular section line 55 of Fig. 2,

Fdig. 6 is a plan view of the magnet core; an

' Fig. 7 is a rear elevationrof the magnet core.

In the particular form shown, the im-' proved signal horn comprises front and rearportions or sections 10, 11, between which is interposed a sound-emitting diaphragm 12. This diaphragm is usuallyof metal, for example a phosphor bronze alloy. The rear section 11 of the horn is in the form of a closed casing having an open flared forward end over which the .diaphragm is clamped, preferably by means of small bolts 13 passing through openings in the enlarged rear end portion 10 of the section 10, and

through registering openings in-the periphcry of the diaphragm and the periphery or rim of the casing 11. Within the casing 11, an electromagnet 14: is mounted which acts on a suitable armature 15 directly carried by the diaphragm 12. The electromagnet 14 is appropriately connected by means of binding posts 16, 17 with a suitable source of alternating current, such as the magneto of the automobile motor. By preference, the electromagnet is constructed in the following manner: The core 18 (Figs. 6 and 7 is of laminated form, being made of a plurality of superposed steel sheets stamped out in approximately horseshoe form andriveted together by pins 19. These pins 19 also pass through angle plates or brackets 20 by means of which the magnet is secured in place in the casing, the brackets being riveted to the end wall of the casing by rivets 21 (Fig. 3) passing through perforations 22 (Fig. 7) in the respective plates or brackets. After the core 18 has been. mounted in the casing in the .'manner described, an insulating plate or sheet 23 having openings for the legs or branches of the magnet core is slipped over 3 said core into the position shown so as to form asupport and insulator for wire coils 24, one of which embraces each leg or branch er thecore. The coils 24 are preferably formed of thin copper wire and covered with binding tape, and they may be tightly held the armature member carried by the "diaphragm. Each of the wire coils 24 is very efiectively insulated from the metal .casing' by the insulating member23, which may ad vantageously consist of a sheet or plate of fibrous insulating material, and this sheet or plate, together with the wire coils, is efiectively held in place bybending up the laminations of the core in the manner previously described. In bending up the laminations pressure is exerted on the coils and on the insulating member back of the same in the direction of the rear wall of the case so as to holdsaid parts firmly in position, and thereby prevent any looseness or dislocation of theassemblage. I

By preference, the armature member 15 is constituted by a steel button, the relation of which to the magnet core is substantially that shown'in Fig. 4 In this view, the core ends, designated 18, 18 are shown as located in parallelism on opposite sides of the center of the armature disk or button. This disk or button is preferably constituted by a .7 single fairly thin piece of sheet metal as shown and is carried by a screw 25 having a threaded shank which engages an interiorly threaded bushing 26 on the diaphragm. The bushing 26 is preferably set and clenched in a central perforation in the diaphragm. vBy turning the screw 25 in one or the other direction by means of a screw driver engaging the nick or groove 27, the

armature ,button or disk may be moved toward or away from the electromagnetto the desired extent; After it is adjusted to the desired position, it may be tightly clamped in that position by means of a lock'or jam nut 28. Figs. 2 and 3 show the armature disk or member in two different adjustments respectively. The bushing 26 is disposed forthe most partatthe front of the diaphragm 12, but has a reduced neck portion extending rearwardly through a central opening in the diaphragm and clenched in said opening so as to prevent the bushing from rotating relatively to the diaphragm. This bushin serves as a support for the threaded shan or screw 25. When the jam nut 28 is tightened, it abuts the front edge .of the bushing and exerts such a thrust on t escrew as to lock it effectively against acci ental'turning matter turb the adjustment.

The source of alternating current may be constituted by the ignition magneto of the automobile. In Fig. 1 the cu'rrentsource is indicated diagrammatically at 29, it being connected withthe binding posts 16, 17 by suitable wires or conductors. A switch 30 for 'openin and closing the circuit is usually'locate in practice onthe steering post of the automobile. When the switch is closed, the alternating current passes through the coils 24 of the electromagnet .movement in the bushing which would dis- 14, and thereby energizes the latterso as to "cause the vibration of the sound-emitting diaphragm 12. Suppose that with the parts in the position shown in Fig. 5, the current passes through the electromagnet in one direction, the poles of the magnet will attract thearmature member 15 and thereby move the central part of the flexible diaphragm toward the magnet. This produces a movement of the diaphragm in one direction, and

' then as the direction of the current in the coils 24 is reversed, the diaphragm moves back to the initial position. In this way, the

diaphragm is vibrated in correspondence.

disk in substantially parallel zones. Thisarrangement has given very good results in actual practice.

When the diaphragm is vibrated without,

contact of. the armature with the magnet, the tone produced is what may be termed a sus vtaine'd musical tone. Generally, however,

the, armature 15 will be so adjusted by means of the screw 25 that at the limit of its movement in one direction it will strike the poles of the magnet, thereby giving the effect of a sharp hammer blow. This produces a peculiar raucous noise which readily attracts attention in crowded thoroughfares. The rapidity of these hammer blows, which take place on the rearward movement of the diaphragm only, is obviously dependent upon the frequency. of the current and the speed of the magneto. In producing these hammer blows, the diaphragm is moved in a direction counter to the emission of the sound waves from the horn. This enables me to use a very simple combination of parts, while obtaining at the same time an unexpectedly loud tone. I

The bending up of the laminations at the free ends of the pole portions of the magnet core serves to hold the energizing coils away from the extremities of the core and to prevent the coils from making-contact with the" armature disk or button, and thereby mufflingjthe sound. It willbe observed that the casing 11, which'fis made oflight sheet metal in the embodiment shfhwn, is of cylindrical form at the rear portion thereofepresenting i considerably to form a flaringmouth portion, over which the diaphragm is located.

"The casing is preferably made of a single piece of drawn metal, as in the example shown, the magnet structure being riveted to the closed rear wall thereof and the dial hragm being clamped over the flared open ront end by the fastening bolts.

By adjustment of the armature disk or Hutton, thelatter may be moved into such position with respect tothe magnet as to produce the kind of signal desired, 13. e., one

' in which the interruption of the musical in addition to'the raucous noise vibration by the hammer blows is more or less pronounced. Obviously, the tone changes with the speed of the motor, so that the hammer blows (contact"o magnetand armature), the-sound is higher and 'shfriller: as the motor speed increases. Thus,

in crowded trafi the horn will produce a siren effect when it is sounded at the moment that the clutch is slipped to reduce speed,

and the motor: is thereby accelerated. v Variouschanges inthe details of the de-, vice may be adopted without departing from the scope of the invention. as defined in the I claims-f Y Whatl' claini 1. In a signal horn, the combination of a diaphragm, a casing located at the rear "of the diaphragm, a magnet core composed, of a. plurality of laminations, angle plates between, which the rear" portions of said laminations are interposed, fastening members extending through the rear wall of the casing and through said angle plates for securing said angle plates to said wall, an

insulating member fitting over said magnet 'core infront of said angle plates, a coil on said magnet core in front of said insulating member,,and' an armature button supported by said diaphragm at the rear face thereof in, proximlty to the poles of said magnet core; substantially asdescribed.

2. In a signal born, the combination of a diaphragm, a casing at the-rear of the dia-' phragm, a magnet core composed of a plurality of laminations, plates or brackets secured to theyi ear. wall of the casing and having forwarfdly projecting portions between whichsaid laminations are interposed and secured, said magnet core having a forwardly extending pole member, an insulating member fitting .over said pole member reduced I gi'zing coil fitting over said ole member, certain laminations of said po e member be-' ing bent up tohold the coil firmly in place,

,and an armature carried by the diaphragm a forwardly extending pole member, an insulating member fitting over said pole mem her in front of saidplates, an energizing coil fitting over said pole member infrontof said'insulating member, means-at the forward'end of the pole member for preventing dislocation thereon of said insulating mem-. her and said coil, and an armature carried by said diaphragmgsubstantially as described.

.in front of said plates or brackets, an ener- I .4. Ina signal horn,- the combination of a diaphragm, a casing at the rear of said diaphragm, a magnet core composed of a 'plu rality of laminations, said core having forwardly extendlng pole portions, plates or brackets secured to a wall of the casing and having forwardly projecting portions be-i tween which said laminationsare. interposed and secured at their rear portions, an insulatmg plate fitting over at least one of said pole portions in front of said portion in front of said insulating plate, the, laminations of said pole portion be bent up at the'front ends to hold said (30' in posltion, and anarmature member to eooperate with said magnet core eonn with the diaphragme-substantially as described. i

5. In a signal horn, the combination of a diaphragm, a casing at the rear. of the diaphragm a horseshoe ma et core composed of a plurality of laminations, plates or brackets secured to the rear wall of the easing and having forwardl projecting portions between which sai laminations are interposed and secured, an insulating plate fitting over the pole portions of said magnet in front of said plates or brackets, coils fitting over the respective pole portions in front of said insulating plate, the laminanamed plates, a coil'fitting over said pole Ifitl new tions of said core, being bent up to hold said coils in position on the respective pole portions, and an armature connected with the diaphragm ,jcofiperate with said magnet core; substantially as described.

6. In a signal horn, the combination of a flo- screw or shank engaging screw threads in said bushin and extending rearwardly through sai shank having means at the forward end thereof, whereby it may be screwed forwardly or rearwardly, and an armature disk carried by the, rear end portion of said screw or shank close to and facing the poles of said magnet core; substantially as described. 7 7 In a signal horn, the combination, with the horn proper and the diaphragm at the rear of the same, of a casing at the back of the diaphragm, a magnet mounted in said casing and comprising a core and an energizing coil, said core having parallel forward extremities adjacent to said diaphragm, an armature at the rear of the diaphragm composed of a disk made of a single piece of metal and having portions on opposite sides of the center facing the poles of said core, a bushing exten forwardly from said diaphragm and having its rear gaging the threads of said bushing and 'ex-.

diaphragm, said screw or end non-rotatively secured in an opening disk, and a lock nut on the forward end of said screwlin front of said. bushing; sub-,-

stantially as described. I

8. In a signalhorn, the'combination of. a diaphragm, a casing at the rear of the same, a magnet in said casing comprising a core and an energizing coil, a. bushing extending forwardly fromsaid diaphragm but having. a reduced neck portion clenched in anopening of the diaphragm, said bushing provided with interior screw threads, a screw engaging said threads and having a grooved end protruding from the front end of said bushing, a lock nut engaging-the forward end of said screw and adapted to abut the forward end of said bushing, and an armature button carried by the rear end of said I screw to cooperate with the magnet core; substantially as described.

In witness whereof, I have hereunto set my hand on the 22nd day of July, 1915.

, f DWIGHT B. nna

Witness:

' (II-I, Parnason. 

